Every week, it seems, there’s a new breakthrough in 3-D printing that promises us the ability to (eventually) fabricate some new thing in one of those glass-walled wonder boxes. Such things have included everything from spare parts for the International Space Station above to the beef on our dinner plates to the organs inside our bodies. Although this last idea of fabricating body parts may seem the most fanciful, a team of scientists is reporting a breakthrough in 3-D printing using human embryonic stem cells that could purportedly lead to life-like bioengineered tissue and, eventually, artificial organs tailor-made for specific patients.